Rail Coupling Drawbar Centering With Spring-Supported Linkage

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Solution Overview

Problem

Existing articulation devices for rail vehicles fail to maintain the coupling head in an optimal vertical position and ensure automatic return to a central starting position after decoupling, particularly in freight wagons where simpler and cost-effective designs are required without irreversible energy absorption elements.

Innovation Solution

A structurally simple articulation device featuring a guide rod with a compression spring, a spherically integrated flexible rubber bush, and an adjustable support mechanism that secures the pull rod and coupling head, preventing twisting and ensuring central return through compressive force activation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a simple and inexpensive construction is used for the articulation device, then the device complexity and manufacturing cost are reduced, but the ability to maintain the coupling head in an optimal vertical position and ensure automatic return to central position deteriorates

Engineering Contradiction:
Improveconstruction simplicityVSAvoidposition maintenance and automatic return
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The articulation device is divided into functionally independent segments: the connecting arm for lateral support, the guide rod for vertical positioning, and the compression spring for automatic return. This segmentation allows each component to perform its specific function simply and effectively, resolving the contradiction between simplicity and reliability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The compression spring provides automatic return to the central starting position without requiring external actuation or complex control systems. The spring self-generates the necessary force to restore the coupling head to its optimal position after decoupling, maintaining reliability while keeping the construction simple.

Inventive Principle:
Principle #25Self-service

2Device complexity

If irreversible energy absorption elements such as expansion tubes are omitted to simplify the construction, then the device complexity is reduced, but the damping capability of tensile and compressive forces deteriorates

Engineering Contradiction:
Improveconstruction simplicityVSAvoiddamping capability
Core Design Contradiction:
Device complexityVSForce

Solution Approach 1:

The patent changes the damping mechanism from irreversible energy absorption (expansion tubes) to reversible elastic energy storage (compression spring). The spring constant and pre-load can be adjusted to provide appropriate damping forces for tensile and compressive loads, maintaining force absorption capability while simplifying the construction by eliminating irreversible energy absorption elements.

Inventive Principle:
Principle #35Parameter changes

3Ease of operation

If the coupling head is held in a position protruding vertically as far as possible, then the coupling function is optimized, but the device complexity increases to maintain this position

Engineering Contradiction:
Improvecoupling functionVSAvoidposition maintenance mechanism
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The compression spring is configured to provide equalizing forces that maintain the coupling head in the optimal vertical position regardless of lateral displacements or coupling variations. This creates an equipotential condition where the coupling head naturally returns to the desired position, simplifying the maintenance mechanism while optimizing coupling function.

Inventive Principle:
Principle #12Equipotentiality

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The device securely maintains the coupling head at the desired height, automatically returns it to a central position after decoupling, and prevents twisting of the pull rod, providing a cost-effective and operationally reliable solution for rail vehicle coupling systems.

Implementation Method 1

a compression spring (7) surrounding said guide rod (8), said compression spring (7) acting on the one hand on said support (4) and on the other hand on a holder (2') of said pull rod (2) for generating this supporting pressure force

Methodology Applied
Scientific EffectCompression spring: Spring

Implementation Method 2

the support (4) is provided with a spherically integrated flexible rubber bush for the guide rod (8) of the connecting arm (6)

Methodology Applied
Scientific EffectFlexible rubber bush: Elasticity

Implementation Method 3

after decoupling it automatically returns the drawbar with the coupling head or similar to the central starting position by pull rod is automatically returned to the central position by the compressive force of the connecting arm during deflection movements

Methodology Applied
Scientific EffectCompression spring force: Spring

Data Source

PatentEP3792136B1Steering device for a coupling, especially for a rail vehicle
Publication Date: 2023.07.26 FAIVELEY TRANSPORT SCHWAB AG
  • EP3792136B1 patent drawingFigure 1~3

AI summary

A linkage device (1) for a coupling, particularly of a rail vehicle, is provided with a drawbar (2), a support (4) connectable to the rail vehicle, and several spring elements (3) arranged on the drawbar (2) on both sides of the support (4) that holds the drawbar (2) for damping the compressive and tensile forces generated during coupling. The drawbar (2) for deflecting it is mounted in a pivot joint (5) arranged in the support (4) between the spring elements (3). A connecting arm (6), preferably aligned parallel to the drawbar (2), is arranged between the support (4), the at least one spring element (3), and the drawbar (2). This connecting arm (6) connects the drawbar (2) to the support (4) in such a way that a supporting compressive force is generated on the drawbar (2), thereby ensuring at least a certain centering vertical position of the drawbar.